Sanitary milk-pump.



K. D. SMITH.

SANITARY MILK PUMP.

APPLICATION FILED OCT. 3. 1914.

1,203,923. Patented Nov. 7, 1916.

Gum/um;

INC mums PETERS co. PNOYU-LITHQ. wAsnmdmx n, c

secured to the ends thereof by the bolts 3 eras rarnisr anion.

KARL D. SMITH, OF BATTLE CREEK, MICHIGAN, ASSIGNOR TO UNION STEAM PUMP COMPANY, OF BATTLE GREEK, MICHIGAN.

SANITARY MILK-PUMP.

Specification of Letters Patent.

ratemea Nov. a, rare.

Application filed. October 3, 1914. Serial No. 864,932.

To all whom it may concern I sanitary milk pumps.

The objects of this invention are: First, to provide an improved sanitary milk pump which will meet the most strict and exacting requirements of the sanitary laws 'relatmg to the handling of milk. Second, to provide an improved sanitary pump which can be easily taken apart for cleaning and sterilization and in which there are no sharp corners, cracks, crevices or other inaccessible places in which the dirt and germs can lodge. Third, to provide an improved pump without any lift valves whatsoever employed.

Further objects, and objects relatmg to details and economies of construction and operation, will definitely appear from the detailed description to follow.

I accomplish the objects of my invention by the devices and means described in the following specification.

The invention is clearly defined and pointed out in the claims.

A structure constituting a preferred embodiment of my invention is illustrated in the accompanying drawings forming a part of this specification, in which:

Figure I is a view partly in section and partly in elevation, the pump cylinder being cut in half to show the piston 1n elevation. Fig. 11 is a longitudinal sectional view on the line 22 of Fig. III. Fig. 111 is a transverse sectional view on the irregular line 33 of Fig. 11.

In the drawings, similar reference characters refer to similar parts throughout the several views, and the sectional views are taken looking in the direction of the little arrows at the ends of the section lines.

Considering the numbered parts of the drawing, the cylinder 1 has the heads 2, g and is provided with the inlet port 4: and the outlet port 5. A piston works within said cylinder, said piston comprising a piston cylinder 6 and the piston members 9 and 10 hereafter to be described. The piston cylinder 6 is provided at the ends thereof with annular flanges 6 6 having a sliding engagement with the wall of the pump cylinder 1. The piston cylinder also is provided, at diametrically opposite points thereon, with the webs or bridge 7 formed integral with the piston cylinder having a sliding engagement with the wall of the pump cylinder 1 throughout the length of the piston cylinder, said web dividing the space between the flanges 6 at the ends of the piston cylinder into a lower or intake chamber and an upper or discharge chamber. Ports 8, consisting of elongated slots, are cut in the piston cylinder, a pair of intake ports being provided in the lower part of the piston cylinder opening into the intake chamber and a pair of discharge ports being provided in the upper part of the piston cylinder communicating with the discharge chamber. The discharge ports are slightly offset relative to the intake ports. These ports afford communication between the intake and discharge chambers respectively and the inte rior of the piston cylinder.

Within the piston cylinder there are slidably disposed a pair of piston members 9 and 10 which have a sliding engagement with the piston cylinder and which, together with the flanges of the piston cylinder, form the piston of the pump. These piston members 9 and 10 have annular flanges 9 and 10 extending oppositely from each other and having a sliding engagement with the wall of the piston cylinder. A piston rod 12 passes through one of the cylinder heads 2 and through the piston members 9 and 10. The end of said piston rod 12 is reduced and threaded and has a shoulder 12 against which thewasher 13 is seated. Nuts 14.- are threaded on the end of the piston rod beyond the piston members and cooperate with the washer13 and shoulder 12. to hold the two piston members together and to secure them to the piston rod. A port 11 is provided in the flange of each piston member, said port opening upwardly and being disposed so as to be brought into alinement with the corresponding discharge port 8. The ports 11 are so disposed relative to the ports 8 that, when the port 11 in one flange is brought into alinement with the corresponding discharge port, the flange on the other piston member is moved so as to open the corresponding intake port. It will thus be seen that when the intake chamber is in communication with the cylinder on one side of the piston, the discharge chamber is in communication with the piston on the other side of the piston. The piston members 9 and 10 are provided with recesses or slots 16 which, when the parts are assembled, are brought into alinement with each other, and a pin 15 carried by the wall of the piston cylinder is disposed in said slots 16. This allows a limited amount of movement of the piston members relative to the piston cylinder, the purpose of which will be hereinafter set forth.

From the description of the parts g ven above, the operation of the device will be very readily understood. In the drawings, the parts are shown in the position they take at the end of the stroke toward the left. At this time the liquid has been drawn into the right end of the cylinder 1 through the right hand intake port 8. When the piston rod 12 starts on its movement back toward the right, it pulls the inner piston members 9 and 10 toward the right until the pin 15 strikes the left hand end of the slot 16. This moves the piston members relative to the piston cylinder so that the flange 10 closes the right hand intake port 8 and the flange 9 moves to one side so as to open the left hand intake port 8. At the same time, the movement of the flange lObrings the right hand port 11 in alinement with the right hand discharge port 8 of the piston cylinder, while the left hand port 11 of the piston member has moved out of alinement with the left hand discharge port 8 of the piston cylinder. It will thus be seen that the liquid flows from the inlet and the intake chamber through the left.

hand intake port v8 into the space at the left end of cylinder 1. As the piston rod 19- continues to move toward the right it carries with it the piston members and the piston cylinder and the liquid in the right end of the piston cylinder is forced out through the right port 11 and the right discharge port 8 into the outlet chamber, while liquid is drawn in through the inlet chamber and the left hand intake port 8 into the space at the left end of the cylinder 1. IVhen the piston rod starts to move back toward the left again, the inner piston members are first moved so as to bring them into relation with the piston cylinder as shown in Figs. I and II and the liquid is then forced from the left end of the cylinder 1 through the left hand ports 11 and 8 into the discharge chamber and is drawn in through the inlet port and inlet chamber and the right hand intake port 8 into the right end of the cylinder 1.

' When it is desired to take the pump apart for cleaning and sterilizing, all that needs to be done is to remove one of the cylinder heads, remove the piston cylinder and the piston members, and by unscrewing the nuts 14 separate the piston members 9 and 10. All of the parts can then be removed for cleaning. It will be seen that there are no cracks, crevices or inaccessible places and that all the surfaces are smooth so that they can be very effectively sterilized and do not afford any opportunity for dirt or germs to lodge.

This pump is especially designed for a sani tary milk pump to meet with the most exact ing requirements of the sanitary laws relat ing to the handling of milk and it is for this reason that it is essential that provision be made for a quick and effective disassembling and cleaning of all of the parts. l/Vhile this pump is especially designed as a milk pump,

it will be readily seen that it is useful for very many other purposes and makes a very effective double acting pump for any purpose whatsoever.

am aware that the particular embodiment of my invention, which I have herein shown and described, is susceptible of considerable variation, without departing from the spirit of my invention and, therefore, I

do not wish to be restricted to the same. I

class described, pump cyhnder prodischarge openings, a

piston cylinder disposed within said pump" cylinder and provided with annular flanges at the ends thereof, having a sliding engage ment with the wall of the pump cylinder, webs formed integral witl said piston cylinder and extending between said flanges at diametrically opposite points on said piston cylinder, said webs having a sliding engagement with the wall of the pump cylinder and dividing the space between the flanges of said piston cylinder into an intake chamber and a discharge chamber, a pair of intake ports in said piston cylinder communicating with the said intake charge ports in said piston cylinder communicating with said discharge chamber. said discharge ports being staggered rela tive to said intake ports, a two part piston chamber, a pair of disdisposed within said piston cylinder in slidflanges, a port so disposed in its piston flange that, when it is in alinement with the corresponding discharge port, said piston flange closes the corresponding intake port while the other piston flange is disposed to close the corresponding discharge port and to open the tially as described and for the purpose speci- 2. In a structure of the class described,

the combination of a pump cylinder provided with inlet and discharge openings, a

piston cylinder disposed within said pump cylinder and provided with annular flanges at the ends thereof. having a sliding engagement with the wall of the pump cylinder, webs formed integral with said piston cylinder and extending between said flanges, said webs having a sliding engagement with the wall of the pump cylinder and dividing the space between the flanges of said piston cylinder into an intake chamber and a discharge chamber, a pair of intake ports in said piston cylinder communicating with the said intake chamber, a pair of discharge ports in said piston cylinder communicating with said discharge chamber, said discharge ports being staggered relative to said intake ports, a two part piston disposed within said piston cylinder in sliding engagement therewith and having a limited sliding movement relative thereto, the parts of said piston being provided with oppositely extending annular flanges, a port in each of said flanges adapted to be brought into alinement with one of the discharge ports of the piston cylinder, each port beingso disposed in its piston flange that, when it is in alinement with the corresponding discharge port, said piston flange closes the corresponding intake port while the other piston flange is disposed to close the corresponding discharge port and to open the corresponding intake port, a slot in each part of said piston, said slots being in alinement when the parts of the piston are assembled, a pin carried by the wall of the piston cylinder and disposed in said slots to limit the movement of said piston relative to the piston cylinder, a piston rod, and means securing the parts of said piston together and to said piston rod, all coacting substantially as described and for the purposes specified.

3. In a structure of the class described, the combination of a pump cylinder provided with inlet and discharge openings, 21-

piston cylinder disposed within said pump cylinder and provided with annular flanges at the ends thereof, having a sliding engagement with the wall of the pump cylinder, webs formed integral with said piston cylinder and extending between said flanges, said webs having a sliding engagement with the wall of the pump cylinder and dividing the space between the flanges of said piston cylinder into an intake chamber and a discharge chamber, a pair of intake ports in said piston cylinder communicating with said intake chamber, a pair or" discharge ports" in said piston cylinder communicating with said discharge chamber, a two part piston disposed within said'piston cylinder in sliding engagement therewith and having a limited sliding movement relative thereto, the parts of said piston being provided with oppositely extending annular flanges, a port in each of said flanges adapted to be brought into alinement with one of the discharge ports of the piston cylinder, each port being so disposed in its piston flange that, when it is in alinement with the corresponding discharge port, said piston flange closes the corresponding intake port while the other piston flange is disposed to close the corresponding discharge port and to open the corresponding intake port, a slot in each part of said piston, said slots being in alinement when the parts of the piston are assembled, a pin carried by the wall of the piston cylinder and disposed in said slots to limit the movement of said piston relative to the piston cylinder, a piston rod, and means securing the parts of said piston together and to said piston rod, all coacting substantially as described and for the purpose specified.

a. In a structure of the class described, the combination of a pump cylinder provided with inlet and discharge openings, a piston cylinder disposed within said pump cylinder and provided with annular flanges at the ends thereof. having a sliding engagement with the wall of the pump cylinder, webs formed integral with said piston cylinder and extending between said flanges, said webs having sliding engagement with the wall of the pump cylinder and dividing the space between the flanges of said piston cylinder into an intake chamber and a discharge chamber, a pair of intake ports in said piston cylinder communicating with said intake chamber, a pair of discharge ports in said piston cylinder communicating with said discharge chamber, a two part piston disposed within said piston cylinder in sliding engagement therewith and havinga limited sliding movement relative thereto, the parts of said piston being provided with oppositely extending annular flanges, a port in each of said flanges adapted to be brought into alinement with one of the discharge ports of the piston cylinder, each port being so disposed in its piston flange that, when it is in alinement with the corresponding discharge port, said piston flange closes the corresponding intake port, while the other piston flange is disposed to open the corresponding intake ports, and to close the cor responding discharge port, means connecting said two part piston and said piston cylinder and permitting a limited movement of said two part piston relative to said piston cylinder, a piston rod, and means securing the parts of said piston and to said piston rod, all coacting substantially as described and for the purpose specified.

5. In a structure of the class-described, the combination of a pump cylinder provided with inlet and discharge openings, a piston cylinder disposed within said pump cylinder and provided with annular flanges atthe ends thereof, having a sliding engagement with the wall of the pump cylinder, means dividing the space between the flanges of said piston cylinder into an intake chamber and a discharge chamber, a pair of intake ports in said piston cylinder communicating with said intake chamber, a pair of discharge ports in said piston cylinder communicating with said discharge chamber, a two part piston disposed within said piston cylinder in sliding engagement therewith, and having a limited sliding movement relative thereto, the parts of said piston being provided with oppositely extending annular flanges, a port in each of said flanges adapted to be brought into alinement with one of the discharge ports of the piston cylinder, each port being so disposed in its piston flange, that when it is in alinement with the corresponding discharge port, said piston flange closes the corresponding intake port, while the other piston flange is disposed to close the corresponding discharge port and to close the corresponding intake port, means for 'connecting said piston with said piston cylinder, and permitting a limited movement of said piston relative to said piston cylinder, a piston rod, and means securing the parts of said piston together and 'to said piston rod, all c'oacting substantially as described and for the purpose specified.

6. In a structure'of the class described, the combination of a pump cylinder provided with opposed inlet and discharge openings,a pump piston comprisinga cyl-' inder-like body portion provided With flange-like heads at its ends with longitudinal webs extending between said heads dividing the-space between the heads into an intake and a discharge chamber with which said inlet and discharge ports open respectively and are in constant communlcation,

nately brought into register With the dis-' charge ports of said piston, the inlet'ports belng closed whlle the discharge ports are open, the lost motion connectlon between the valve piston and the pump piston being such that on each stroke of the valve piston the inlet port at the discharge end of the piston is first closed and the discharge port at that end then opened and the piston then actuated.

In witness whereof, I have hereunto set my hand and seal in the presence of two witnesses.

KARL D. SMITH. [Ls] IVitnesses C. IN. BRAINERD, E. REEVES.

Copies of this patent may be obtained for five cents each, by, addressing the Commissioner of Patents,

' Washington, D. C. 

